So I'm not sure how far the realm of gestures reach (commonly referenced in the roadrunner forums as annoying red dots) but here's a link to a device someone rigged up to control gestures with a laser pointer:
FRIGGIN LASER!
From my 30 seconds of review I believe it works from a webcam reading the laser off a wall in the dark. Not extremely practical as of now but if you read the bottom you can see the thoughts of using infrared and a frequency isolator to make it daytime useful and invisible. That would produce a "one button" remote control for as many commands as you can uniquely determine.